An official website of the United States government
Abstract Understanding prehistoric projectile weaponry performance is fundamental to unraveling past humans’ survival and the evolution of technology. One important debate involves how deeply stone-tipped projectiles penetrate a target. Theoretically, all things being equal, projectiles with smaller tip cross-sectional geometries should penetrate deeper into a target than projectiles with larger tip cross-sectional geometries. Yet, previous experiments have both supported and questioned this theoretical premise. Here, under controlled conditions, we experimentally examine fourteen types of stone-tipped projectile each possessing a different cross-sectional geometry. Our results show that both tip cross-sectional area (TCSA) and tip cross-sectional perimeter (TCSP) exhibit a strong, significant inverse relationship with target penetration depth, although TCSP’s relationship is stronger. We discuss why our experimental results support what is mathematically predicted while previous experiments have not. Our results are consistent with the hypothesis that when stone tip cross-sectional geometries become smaller over time in particular contexts, this evolution may be due to the selection of these attributes for increased penetration.
more »
« less
Ancestral Stones and Stone Stories: Reimagining Human Relationships with Stone from the Paleolithic to the Present
We begin the special issue with an Editorial that focuses on the origin of the workshop and our Stone Stories. Each scholar conveyed at the workshop a personal story that epitomized their relationship with stone. Each story is a unique journey demonstrating how we listened and learned from childhood experiences, elders, and Indigenous communities. Our paths demonstrate how scholars can learn to put aside their Western perceptions and reconceive the world through other ontologies.
more »
« less
- Award ID(s):
- 1916933
- PAR ID:
- 10530650
- Editor(s):
- Arthur, Kathryn W; Barkai, R
- Publisher / Repository:
- Archaeologies
- Date Published:
- Journal Name:
- Archaeologies
- Volume:
- 20
- Issue:
- 1
- ISSN:
- 1555-8622
- Page Range / eLocation ID:
- 1 to 23
- Subject(s) / Keyword(s):
- stone, ontology, archaeology
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Boreda Indigenous knowledge prescribed that humans respect all entities with whom they co-inhabit, including stone. Humans, stone, and water’s reciprocal relationships prompted their participation in each other becoming fetuses, infants, children, youth, married adults, mature adults, elders, and ancestors. Life was a co-production between humans and non-humans, such that stone and water could inflict harm or bring well-being to humans. Non-human beings, such as flaked stone tools, were evidence of engaging in correct interaction ‘practice’ (time, place, and actor) with other beings – a process of mutual respect and responsibility and one in which there was no end or final “product”.more » « less
-
Abstract Backing is a procedure for retouching a stone tool edge to an angle of or near 90°. Archaeologists have recorded backed lithic specimens in the Pleistocene and Holocene around the world. One prominent hypothesis for the occurrence of backing is that it increases a stone tool's adhesion relative to what it would have otherwise been with unmodified, sharp edges. We conducted a highly controlled semi‐static tensile test in which we assessed lithic specimens that possessed both a backed and a non‐backed edge, opposing each other. We hafted each specimen's backed and non‐backed edges to wood, and the bi‐hafted stone implement was then pulled apart using an Universal Instron Materials Tester, allowing for a direct ‘head‐to‐head’ comparison of the two edge types’ adhesive properties. Our tensile test results suggested no significant difference between backed and non‐backed edges in terms of adhesion, which does not support the hypothesis that backing increases a lithic specimen's adhesion.more » « less
-
Many marine species have been shown to be threatened by both ocean acidification and ocean warming which are reducing survival, altering behavior, and posing limits on physiology, especially during earlier life stages. The commercially important Florida stone crab, Menippe mercenaria , is one species that is affected by reduced seawater pH and elevated seawater temperatures. In this study, we determined the impacts of reduced pH and elevated temperature on the distribution of the stone crab larvae along the West Florida Shelf. To understand the dispersion of the larvae, we coupled the multi-scale ocean model SLIM with a larval dispersal model. We then conducted a connectivity study and evaluated the impacts of climate stressors by looking at four different scenarios which included models that represented the dispersion of stone crab larvae under: 1) present day conditions as modelled by SLIM for the temperature and NEMO-PISCES for the pH, 2) SSP1-2.6 scenario (-0.037 reduction in pH and +0.5°C compared to present-day conditions), 3) SSP2-4.5 scenario(-0.15 reduction in pH and +1.5°C) and 4) SSP5-8.5 scenario (-0.375 reduction in pH and +3.5°C). Our results show a clear impact of these climate change stressors on larval dispersal and on the subsequent stone crab distribution. Our results indicate that future climate change could result in stone crabs moving north or into deeper waters. We also observed an increase in the number of larvae settling in deeper waters (defined as the non-fishing zone in this study with depths exceeding 30 m) that are not typically part of the commercial fishing zone. The distance travelled by larvae, however, is likely to decrease, resulting in an increase of self-recruitment and decrease of the size of the sub-populations. A shift of the spawning period, to earlier in the spring, is also likely to occur. Our results suggest that habitats in the non-fishing zone cannot serve as a significant source of larvae for the habitats in the fishing zone (defined as water depth< 30 m) since there is very little exchange (< 5% of all exchanges) between the two zones. These results indicate that the stone crab populations in Florida may be susceptible to community fragmentation and that the management of the fishery should consider the potential impacts of future climate change scenarios.more » « less
-
This guided, inquiry-based, hands-on lesson uses data from a local monitoring station in Tampa Bay, Florida, to guide students toward understanding how coastal acidification may impact the reproductive success of the Florida stone crab, an important regional fishery. The objectives of the lesson are for students to: (1) determine how pH varies between different habitats, (2) determine how pH can affect the reproductive success of an important commercial fishery, the Florida stone crab, and (3) evaluate whether exposure to variable seawater pH results in greater reproductive success in stone crabs relative to individuals that are not exposed to pH variability.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1007/s11759-024-09502-y
